Lamp mounting for high intensity light fixture

ABSTRACT

A lighting fixture adapted to receive an elongated high intensity lamp is provided. The fixture includes a pair of socket assemblies spaced apart from each other within the fixture housing with each assembly including a ceramic socket housing adapted to nest in a base of material of high thermal conductivity. The ceramic housing is maintained in position by a spring which also urges the housing toward the other socket assembly to provide the necessary secure electrical connections between the sockets and the ends of the lamp which comprise the lamp terminals.

United States Patent [191 Roth [ LAMP MOUNTING FOR HIGH INTENSITY LIGHTFIXTURE [75] Inventor: Charles Roth, Glen Gardner, NJ.

[73] Assignee: Keene Corporation, New York,

22 Filed: Apr. 13,1973

21 Appl. No.: 350,768

[52] US. Cl. 240/5l.11 R, 240/1 1.4 R, 240/47, 339/56 [51] Int. Cl. H05b33/02 [58] Field of Search. 240/5l.11 R, 51.11 A, 11.4 R, 240/47;339/53-56, 119 L, 112 R, 52 R, 52 S [56] References Cited UNITED STATESPATENTS 3,097,903 7/1963 Moore 240/47 X 3.390.372 6/1968 Kember eta.339/56 X Aug. 27, 1974 6/1968 Ruston 240/47 X ll/l970 Fenn...' 240/5l.11R X Primary Examiner-Richard L. Moses Attorney, Agent, or Firml(ane,Dalsimer, Kane, Sullivan and Kurucz [57] ABSTRACT A lighting fixtureadapted to receive an elongated high intensity lamp is provided. Thefixture includes a pair of socket assemblies spaced apart from eachother within the fixture housing with each assembly including a ceramicsocket housing adapted to nest in a base of material of high thermalconductivity. The ceramic housing is maintained in position by a springwhich also urges the housing toward the other socket assembly to providethe necessary secure electrical connections between the sockets and theends of the lamp which comprise the lamp terminals.

4 Claims, 2 Drawing Figures LAMP MOUNTING FOR HIGH INTENSITY LIGHTFIXTURE BACKGROUND OF THE INVENTION The present invention relates tolighting fixtures and in particular to high intensity lighting fixturesof the type adapted to receive an elongated high intensity lamp such asthe quartz iodine lamps produced by various manufacturers and availablecommercially. Such lamps, in addition to providing a brilliant whitelight, also generate large quantities of heat during operation. It isessential to proper operation of the lamps and to their prolonged lifethat the lamps be used in fixtures designed to draw sufficient heat fromthe lamp to keep its operating temperature within prescribed limits. Theheat generated by the lamps poses a particular problem at the lamp endswhere the filament passes through the sealed ends of the lamp tube to aterminal adapted to mate with an appropriate socket within the lampfixture. Unless provision is made to properly dissipate heat from theterminals, which is on the order of several hundred degrees Fahrenheit,the insulation on the wires feeding the sockets may burn which couldeventually lead to the entire fixture shorting out. Also, unless theheat generated by the glowing filament is dissipated, the bond betweenthe filament and terminal of the lamp may be destroyed, thus ending theuseful life of the lamp.

Most of the heat generated in fixtures of the type described isdissipated by conduction throughout the fixture housing which is cooledby exposure to ambient air. This process is aided by forming the fixturehousing of a material of high conductivity such as aluminum. Theterminals of the lamp, however, must be properly electrically insulatedfrom the housing and thus the socket housings which receive theterminals are conventionally formed ofa ceramic material such asporcelain which has excellent electrical insulation properties and isable to withstand the high temperatures generated. The problem thenarises as to how to dissipate heat from the ceramic socket housings and,at the same time, insure proper electrical connections between thesockets and the ends of the lamp to be received therein. Heretofore, theproblem was solved by utilizing relatively complex, multispringarrangements to maintain the ceramic housings in position.

In view of the above, it is the principal object of the presentinvention to provide a high intensity lighting fixture having animproved socket assembly incorporating simplified means to insure theproper dissipation of heat generated at the terminals of the lampreceived therein while at the same time providing a secure and positiveelectrical connection with the lamp.

A further object is to provide such an assembly which is relativelyinexpensive and simple to manufacture and assemble and can be used withpre-existing fixture designs with little or no modification of the basicfixture design.

SUMMARY OF THE INVENTION The above and other beneficial objects andadvan tages are attained in accordance with the present invention byproviding a lighting fixture of the type adapted to receive an elongatedlamp and including a fixture housing formed of a material having a highthermal conductivity. The fixture'housing includes a pair of socketassemblies spaced apart from each other a distance sufficient to engageterminals mounted at the ends of the lamp. At least one of the socketassemblies comprises a socket base formed of a material of high thermalconductivity affixed to the housing. The socket base includes surfacesthereon defining a nest adapted to receive a lamp socket housing formedof a ceramic or other electrically insulating material seated within thenest and containing the lamp socket. Spring means are provided withinthe fixture adapted to simultaneously retain the socket housing in thenest and bias the socket housing longitudinally toward the other socketassembly.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view of a high intensity light-- DETAILEDDESCRIPTION OF THE PREFERRED EMBODIMENT Reference is now made to thedrawings wherein simi lar components bear the same reference numeral inboth views. Reference is first made to FIG. 1 wherein an improvedlighting fixture 10, in accordance with the present invention, is showncomprising a fixture housing 12 having continuous top, bottom, rear andside walls defining an enclosure having an open front side 14. Thefixture housing is formed of a suitable material of high heatconductivity such as cast or a heavy gauge aluminum. If desired, adecorative veneer may be applied to the exterior surfaces of thefixture. A heat treated lens supported within a suitable temperature andweather resistant gasket removably seals the front surface of thefixture. Fixture 10 may be supported on a mast 16 through which theappropriate electrical connections enter. If desired, a universalmounting (not shown) may be interposed between the fixture and mast tofacilitate adjustment of the fixture in use.

As shown, the fixture is designed to contain an elongated high intensitylamp 18. To this end, a pair of socket assemblies 20 are provided withinthe fixture spaced apart to receive and secure the terminals at the endsof lamp 18. To increase the efficiency of the fixture, a reflector 22 isprovided extending from top to bottom along the interior rear and sidewalls of the housing with portions of the socket assemblies 20penetrating through openings in the side wall reflectors as shown.

The details of the lamp socket assemblies 20 are shown in FIG. 2.Accordingly, each assembly includes a socket base 24 fomied of amaterial of high thermal conductivity. In this regard, the base 24 mayconveniently be cast in a single unit with the fixture housing and, morespecifically, the rear wall of the housing. The

socket base 24 generally comprises a rectangular mem- 7 her, the topsurface of which includes a recess 26 defining a nest for a sockethousing generally designated by the number 28. The socket base 24further includes an integral wall 30 extending upwardly from the frontend of the rectangular member and having wing portions 32 which wrappartially about the sides of the rectangular member.

The socket assembly further includes a socket housing 28 formed of anelectrically insulating material, as for example porcelain or otherceramic. The socket housing 28 comprises an elongated generallyrectangular member having a lower depending portion 34 contoured to nestwithin recess 26 of base 24. The forward end 29 of housing 28 is raisedand includes an opening providing access to a socket 36 mounted in theforward end and designed to receive and make electrical connection witha terminal at the end of lamp 18. To this end, the exact configurationof the socket is determined by the shape of the terminal of the lamp tobe used in the fixture. The surfaces 38 of the raised portion 29 ofhousing 28 surrounding socket 36 are contoured to define a ledge adaptedto receive and support I the end of lamp 18. A cutout 40 is provided inthe front wall 30 of base 24 aligned with socket 36 thereby providingaccess for the terminal end of lamp 18 to socket 36. The socket housingfurther includes an elongated section 31 extending rearwardly from theraised forward end 29 and having a cavity therethrough which terminatesat one end in socket 36. Theelectrical leads 42 for the socket extendthrough the cavity.

A pair of posts 44 and 46 extend upwardly from the rear wall 48 of thefixture housing 12 on opposite sides and spaced rearwardly of socketbase 24. The posts may conveniently be cast integrally with the fixturehousing rear wall and the socket base. As shown, the posts extend abovethe top of socket housing 28. A U- shaped spring 50 having a baseportion 52 secured to post 44 by screw 54 and a pair of legs 56 and 58is also provided. Leg 56 of the spring abuts post 46 while leg 58 abutsthe rear of the raised front portion 29 of socket housing 28 therebyserving to urge the socket housing in the direction of the arrow of FIG.2 until the socket housing raised portion 29 abuts the rear of the wingportions 32 of wall 30 of housing base 24 (as shown in phantom in FlG.1). Screw 54 serves to secure spring 50 in position. In this connection,the height of post 44 is such that legs 56 and 58 of the spring rest onthe top surface of the socket housing and thus serve to urge the sockethousing downwardly so that the depending portion 34 of the sockethousing nests in recess 26 of the socket base. This establishes a firmheat conduction path from the socket housing to the socket base 24. Thesocket base, in turn, serves to conduct heat to the fixture base 48 fromwhich the heat is dissipated to the atmosphere, thus enabling thefixture to operate within its designed temperature range.

ln use, lamp 18 is inserted in the fixture by pushing one of the sockethousings rearwardly (to the position shown in FIG. 2) and inserting thelamp through opening 40 in the housing wall 30 so that the lamp terminalcan engage socket 36. The socket housing is then released enabling thelegs 56 and 58 of spring 50 to separate thereby urging socket housing 28forwardly to the position illustrated in FIG. 1 whereby a firmelectrical contact is established between the lamp terminals and sockets36. While in this position, spring 50 serves the double purpose ofmaintaining a constant longitudinal force urging the sockets 36 ofassemblies 20 toward one another thereby insuring electrical contactwith lamp 18 while at the same time each spring urges its associatedsocket downwardly'insuring a good thermal contact with its associatedhousing base 24. This arrangement is both simple and effective inmeeting the aforementioned objectives.

Having thus described the invention, what is claimed 1. A lightingfixture of the type adapted to receive an elongated lamp havingterminals at the ends thereof, said fixture including: a fixture housingincluding a rear wall formed of a material having a high thermalconductivity and a pair of socket assemblies in said housing spacedapart from each other a distance substantially equal to the length ofsaid lamp and adapted to secure said lamp in said position and provideelectrical connections for said lamp through said terminals wherein atleast one of said socket assemblies comprises: a socket base formed ofa-material of high thermal conductivity affixed to said housing inthermal conductive relationship, said socket base comprising a generallyrectangular member formed integral with said rear wall and includingsurfaces thereon defining a nest having a raised forward end directedtoward the other socket assembly and a top surface spaced above saidfixture housing rear wall; a lamp socket housing formed of anelectrically insulating material seated within said nest and containinga socket therein adapted to receive one end of said lamp; and springmeans affixed to said fixture housing adapted to simultaneously urgesaid socket housing into said nest and bias said socket housinglongitudinally toward the other socket assembly.

2. The invention in accordance with claim 1 wherein said raised forwardportion comprises wall means extending upwardly from the forward end ofsaid memher, said nest includes a recess extending downwardly from saidtop surface, said socket housing includes a depending bottom portioncontoured to fit within said recess and a front portion contoured toabut against the socket base raised forward end, and said spring meanssimultaneously urges said socket housing depending portion into saidrecess and front portion against said i socket base forward end.

3. The invention in accordance with claim 1 wherein said socket extendsfrom the front portion of said housing and further comprising a cutoutin said socket base forward end aligned with said socket and providingaccess to said socket.

4. The invention is accordance with claim 3 further comprising a pair ofspring retaining posts secured to and extending upwardly from saidfixture housing rear wall spaced rearwardly of said socket base forwardend and positioned on opposite sides of said socket base and said springmeans comprises a U-shaped spring having a base portion secured to oneof said posts, a first leg abutting the other of said posts, a secondleg abutting the socket housing front portion and biased to urge saidfront portion longitudinally toward said socket base forward end, bothsaid legs rest on the top surface of said socket housing and said springis further biased to urge said socket housing into said socket basenest.

1. A lighting fixture of the type adapted to receive an elongated lamphaving terminals at the ends thereof, said fixture including: a fixturehousing including a rear wall formed of a material having a high thermalconductivity and a pair of socket assemblies in said housing spacedapart from each other a distance substantially equal to the length ofsaid lamp and adapted to secure said lamp in said position and provideelectrical connections for said lamp through said terminals wherein atleast one of said socket assemblies comprises: a socket base formed of amaterial of high thermal conductivity affixed to said housing in thermalconductive relationship, said socket base comprising a generallyrectangular member formed integral with said rear wall and includingsurfaces thereon defiNing a nest having a raised forward end directedtoward the other socket assembly and a top surface spaced above saidfixture housing rear wall; a lamp socket housing formed of anelectrically insulating material seated within said nest and containinga socket therein adapted to receive one end of said lamp; and springmeans affixed to said fixture housing adapted to simultaneously urgesaid socket housing into said nest and bias said socket housinglongitudinally toward the other socket assembly.
 2. The invention inaccordance with claim 1 wherein said raised forward portion compriseswall means extending upwardly from the forward end of said member, saidnest includes a recess extending downwardly from said top surface, saidsocket housing includes a depending bottom portion contoured to fitwithin said recess and a front portion contoured to abut against thesocket base raised forward end, and said spring means simultaneouslyurges said socket housing depending portion into said recess and frontportion against said socket base forward end.
 3. The invention inaccordance with claim 1 wherein said socket extends from the frontportion of said housing and further comprising a cutout in said socketbase forward end aligned with said socket and providing access to saidsocket.
 4. The invention is accordance with claim 3 further comprising apair of spring retaining posts secured to and extending upwardly fromsaid fixture housing rear wall spaced rearwardly of said socket baseforward end and positioned on opposite sides of said socket base andsaid spring means comprises a U-shaped spring having a base portionsecured to one of said posts, a first leg abutting the other of saidposts, a second leg abutting the socket housing front portion and biasedto urge said front portion longitudinally toward said socket baseforward end, both said legs rest on the top surface of said sockethousing and said spring is further biased to urge said socket housinginto said socket base nest.